Method of overseaming and overseaming sewing machine



Oct. 7, 1958 A. PALUMBO 2,854,937

METHOD OF OVERSEAMINGAND OVERSEAMING SEWING MACHINE Filed April 8, 1953 3 SheetsSheet 1 Oct. 7, 1958 A. PALUMBO 2,854,937

METHOD OF OVERSEAMING AND OVERSEAMIB IG SEWING MACHINE Filed April 8, 1953 v 5 Sheets-Sheet 2 Oct. 7, 1958 A. PALUMBO 2,354,937

METHOD OF OVERSEAMING AND OVERSEAMING sswmc MACHINE Filed April 8, 1953 3 Sheets-Sheet 3 Aka/4w; ZZQMQ States Patent Ofiice "2,854,937 Patented Get. 7, 195% NIETHOD OF (DVERSEAMHNG AND OVERSEAM- ING SEWING MAQHINJE Anthony Palumbo, Moorestown, N. l, assignor to Pola Enterprises, Inc., Moorestown, N. .31., a corporation of New Jersey Application April 8, 1953, Serial No. 3547,5434 4 Uaims. (Cl. l12-=l'l.77)

The present invention relates to overseamiug Suwillr" machines of the type which produces an over-seam at t edge of two pieces of fabric which is usually pl 2' the wrong side of the garment and which produces hidden sein on the flat side.

A purpose of the invention is to obtain more effective anchorage or tacking of the ends of the threads at the beginning of an overseam.

A further purpose is to obtain a more uniform and smooth overseam near the beginning, and particularly to stitch the overseam back over reverse overseaming threads which have previously been formed into a chain and therefore are less likely to pull out.

A further purpose is to provide for tensioning of a preformed chain as it is fed back into the overseam.

A further purpose is to facilitate cutting off the ends of the preformed chain with uniform length on all of the threads.

A further purpose is to guide a preformed chain back into the overseam without engaging the trimmer so that the chain will not be inadvertently cut by the trimmer.

Further purposes appear in the specification and in the claims.

In the drawings I have chosen to illustrate a few only of the numerous embodiments in which my invention may appear, selecting the forms shown from the standpoints of convenience in illustration, satisfactory operation and clear demonstration of the principles involved.

Figure 1 is a side elevation of the overseaming sewing machine of the invention.

Figure 2 is a front elevation of the overseaming sewing machine of the invention.

Figures 3 to 6 are stepwise perspectives, partially diagrammatic showing the formation of the seam in accordance with the invention.

Figure 7 is an exploded perspective of the chain tcnsioning device in accordance with the preferred embodiment in the invention.

Figure 8 is a section taken axially through the central screw showing assembled chain tensioning device and cutter in accordance with the invention.

Figure 9 is a rear elevation of an alternate mounting for the cutter and chain tensioning device.

Figure 10 is an exploded perspective of the presser foot and the uncurling block of the prior art.

Figure 11 is a perspective of the uucurling block of the present invention.

Figure 12 is a vertical section of the presser foot, oncurling block and upper and lower trimmer knives in accordance with the invention.

Figure 13 is a fragmentary top plan view of the uncurling block and upper and lower trimmer knives.

Figure 14- is an enlarged diagrammatic edge elevation of the seam showing e chain buried therein.

Describing in illustration but not in limitation and referring to the drawings:

in the prior art overseaming machines of the Merrow type have been lely used to join together the edges of.

two pieces of fabric, joining the edges against fraying or unravelling. Typical applications are in the sewing of garments such as jerseys, sport shirts and the like. The present invention relates to a Merrow machine of the type primarily disclosed in U. S. Patent No. 1,983,63l, granted December 11, 1934, for Looper Carrier, of which further features are shown in U. S. Patent No. 1,278,973, granted September 17, 1918, U. S. Patent No. 1,649,360, granted November 15, 1927, for Sewing Machine Guide and basically disclosed in U. S. Patent No. 730,944, granted June 16, 1903, for Overseaming Machine.

In the prior practice it has been diflicult to obtain a satisfactory start or tacking of an overseam due to the tendency of the ends of the thread at the beginning of a seam to loosen and permit the seam to open up. The present invention is designed particularly to obtain an anchorage of the initial ends of the threads which will be so formed and positive that the threads cannot pull out and opening up would not be possible unless the threads themselves broke.

In accordance with the invention, the threads are first paid out. In the preferred embodiment, however, the threads are not merely pulled out separately but the overseam is operated to intertwine the threads in a chain, so that the frictional engagement by One thread on another is formally established. This chain initially formed is next preferably out oh and at a predetermined length to establish a uniform amount of chain which is to be included in the overseam and also to equalize the lengths of all threads in the chain. Subsequently the Work. is oversearned, and the chain is initially tensioned so that it cannot become diverted to one side and extend outside the seam, and so that it cannot kink forming bulge in the seam or Wrap around the length of l-oopers. The overseaming is then started in the usual manner to sew the seam on the Work, but the initially tensioned chain is fed into the overseam; as it feeds into the overseam it is bound and buried therein. An extremely neat appearance is obtained, and except for the greater density of the thread near thebeginning of the seam, the observer does not notice the initial end as being different from other parts of the seam.

In order to prevent the possibility that the trimmer knives which trim the edge of the material being seamed immediately prior to seaming might cut the chain which is being fed back into the seam, a guide slot is provided for the chain on the uncurling block of the presser foot.

As well known. in the art, the Merrow machine shown in Figures 1 and 2 comprises a driving pulley 2b, a table 21, a presser bar 22, a presser foot arm 23, a presser foot 24 on the presser foot arm, an uncurling block 25 extending transversely of the presser foot, a needle carrier 26, a hooked needle having its eye near the end 27, an upper looper 28 and a lower looper Stl, all as well known in the Merrow machine. The needle thread is tensioned by tensioning device 31 of the well known Merrow type. The upper looper thread is tensioned by tensioning device 32 and the lower looper thread is tensioned by tensioning device 33 of similar type.

Positioned suitably adjoining the upper and lower loop tensioning devices and preferably further forward in line with the needle, I have added. a chain tensioning device 33' which may conveniently be of the usual Merrow form. As best seen in Figures 7 and 8, it desirably consists of a longitudinally extending screw 34 having a boss 35, which includes a cylindrical guide bearing 36 and an enlarged limiting head 37 which acts as a spring abutment and base. The screw is mounted on a threaded adapter 38 which acts as a nut to clamp the cutter 40 against the boss 36, the cutter having a suitably diagonally extending notch 41 with upwardly diagonally connected cutter blade above the tensioning device. The adaptor is also threaded J1 into the screw of tensioning device 32 to mount the ad ditional tensioning device.

The thread extends through two convex opposed tension cups 43 which surround the tubular portion 36 of the boss, and tension is applied by a spiral spring 44 acting against an adjustment nut 45 on the screw 34 locked by an adjustment locking nut 46.

In some cases it is preferable to mount the chain tensioning device by bracket 47 screwed at 48 to the frame, and extending out to receive the end of the screw 34 and hold it against the boss by nut 50.

The bracket 47 is swingable outwardly as shown by the arrow to vary the length of the chain which will be cut off. Similar adjustment may be accomplished in the form of Figures 7 and 8 by adjusting the cut off knife for height with respect to the mounting on the screw.

As well known in the art, overseaming machines include a lower and usually stationary trimming knife 51 and an upper reciprocating trimming knife 52 both of which extend longitudinally of the seam and ahead of the needle in the direction of progression of the work by the machine.

These knives are best seen in Figures 12 and 13, from which it is evident that they meet along a shearing line which is at the edge of the work in the seam, but prior to scam formation.

The uncurling block 25 extends ahead of the upper trimming knife and suitably above a portion of the lower trimming knife as shown in Figure 13 and has a forward and upwardly flaring guiding surface 53 which accomplishes the uncurling function.

In accordance with the invention a notch 54 is introduced extending in the direction of the seam on the lower surface of the uncurling block, and suitably located far enough to the seam side of the shear line so that the chain of thread passing through the notch 54 will not be cut in the trimmer.

Thus unlike the prior art uncurling block 25, which has no such notch 54 as shown in Figure 10, the uncurling block of the present invention provides a guiding function on the chain.

In the procedure according to the present invention, the first step as shown in Figure 3 is to operate the stitching without any work (cloth) under the needle, thus paying out a chain 55 of threads which consists of the intertwine needle thread, upper looper thread and lower looper thread. This formation of the chain continues until the chain is long enough to reach up to and beyond the cutting edge 42. In Figure 3 for simplicity the presser foot and uncurling block have been :omitted so that the chain is seen progressing from the needle and the loopers. During this operation the presser foot is normally raised, by raising the presser foot arm.

In the next step the presser foot is lowered and the chain is fed through the guiding notch 54 at the lower edge of the uncurling block as the presser foot comes down. The chain is then fed up through the tensioning cups 43 of the chain tensioning device and then carried over the knife edge 42 and the remote end is pulled to cut off the chain eventually at the knife edge as shown in Figure 4.

In the next operation as shown in Figure the presser foot is raised to bring the work or cloth layers 56 and 57 superimposed upon one another under the presser foot to start the seam. The edge 58 which after trimming is to be the seamed edge is lined up properly and the machine started to do the overseaming. As the work feeds in through the needle and upper and lower looper the chain 55 is pulled through the tensioning cups 43 and down in the seam, so that eventually the chain pulls out of the tension cups but continues to feed, no longer requiring tension since it is guided through the notch 54. The final result is to bury the'last of the chain as seen at 60 in the newly formed overseam 61 of Figure 6. The operation is so rapid that it is almost instantaneous and normally cannot even be seen by the eye. Thus as shown in Figure 14 the final overseam 61 has the chain 55 extending therethrough from the beginning 62 as far as the length of the chain permits after which the overseam continues at 63 in the normal manner without any buried chain.

It will thus be evident that in accordance with the invention the beginning of the seam contains the overseaming ends which are brought back on themselves and are very firmly anchored to protect against opening up or bursting.

In view of my invention and disclosure variations and modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art, to obtain all or part of the benefits of my invention without copying the method and apparatus shown, and I therefore claim all such insofar as they fall within the reasonable spirit and scope of my claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. An overseaming sewing machine comprising a needle having an eye near the point, an upper looper c0- operating with the needle, a lowerlooper cooperating with the needle and the upper looper, means for tensioning a needle thread, means for tensioning an upper looper thread, means for tensioning a lower looper thread, a presser foot cooperating with the needle, an uncurling block mounted on the presser foot, cooperating trimmer knives for trimming the work passing into the needle and located at one side of the presser foot, in combination with means, mounted on the machine, for tensioning a chain of thread which consists of the needle thread, the upper looper thread and the lower looper thread and extends from the vicinity of the needle, and means comprising walls forming a notch on the uncurling block to one side of the meeting edge of the trimming knives for guiding the chain into the seam without engaging the trimming knives.

2. An overseaming sewing machine comprising a needle having an eye near the point, an upper looper cooperating with the needle, a lower looper cooperating with the needle and the upper looper, means for tensioning a needle thread, means for tensioning an upper looper thread, means for tensioning a lower looper thread, a presser foot cooperating with the needle, an uncurling block mounted on the presser foot, cooperating trimmer knives for trimming the work passing into the needle and located at one side of the presser foot, in combination with means, mounted on the machine, for tensioning a chain of thread which consists of the needle thread, the upper looper thread and the lower looper thread and extends from the vicinity of the needle, and walls forming a notch on the bottom of the uncurling block to one side of the meeting edge of the trimming knives for guiding the chain into the seam without engaging the trimming knives and a cutoff knife mounted adjacent the means for tensioning the chain and beyond the means for tensioning the chain with respect to the needle.

3. The method of overseaming using a needled thread and looper threads, which comprises overseaming without any work in the seam and thus producing a chain of the needle thread and the looper threads, aligning the chain in front of the needle in the line of feed, cutting off the ends of the chain threads at a predetermined point to produce a fixed length of chain extending from the needle, tensioning the said fixed length of chain, and forming an overseam on work from the same needle thread and looper threads in continuation of the chain while feeding the tensioned chain into the overseam, thus enclosing the said fixed length of chain in the seam.

4. An overseaming sewing machine comprising a body, a work table, a needle having an eye near the point, an upper looper cooperating with the needle, a lower looper cooperating with the needle and the upper looper, means for tensioning a needle thread, means for tensioning an upper looper thread, means for tensioning a lower looper thread, a presser foot cooperating with the needle, an uncurling block mounted on the presser foot, cooperating trimmer knives for trimming the Work passing into the needle and located at one side of the presser foot, means, higher than the work table, remote from the point of the needle and mounted on the body of the machine, for tensioning a chain of thread consisting of the needle thread and the looper threads, and a knife member mounted beyond the means for tensioning the chain with respect to the needle, but adjacent said means, the exact distance between the two being adjustable to any predetermined distance Within a particular range by swinging the knife member, said uncurling block having walls forming a groove on the bottom thereof to one side of the meeting edge of the trimming knives, for guiding the chain into the seam Without engaging the trimming knives.

References Cited in the file of this patent UNITED STATES PATENTS 401,399 Wilcox Apr. 16, 1889 771,434 Mathews Oct. 4, 1904 1,107,669 Hill Aug. 18, 1914 1,202,426 Ray Oct. 24, 1916 1,860,030 Hinchlifi May 24, 1932 2,218,796 Knaus et al Oct. 22, 1940 FOREIGN PATENTS 36,011 Germany July 14, 1886 145,751 Australia Mar. 14, 1952 

